FLUORESCENT LABELING OF A DNA-SEQUENCING PRIMER

Several oligonucleotides containing one to four fluorescein labels in various positions were synthesized and the fluorescence intensity and thermal stability of the duplex forms with their complementary sequenc es were measured. Oligomers that contain two fluorescein molecules, on e attached at the 5' terminus and the other at an internal phosphate, were hybridized with less stability than that containing fluorescein a t only the 5' terminus but it formed more efficient primers for dideox y sequencing with an automated sequencer.